<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="../../reset.css">
    <style>
        .slide-img {
            width: 1000px;
            height: 500px;
            overflow: hidden;
            position: relative;
            margin: 20px auto;
        }

        ul {
            transition: all .5s ease;
        }

        li {
            float: left;
        }

        .slide-arrow div {
            width: 50px;
            height: 100px;
            position: absolute;
            margin: auto;
            top: 0;
            bottom: 0;
            background: url("http://i1.bvimg.com/1949/4d860a3067fab23b.jpg") no-repeat;
        }

        .arrow-right {
            transform: rotate(180deg);
            right: 0;
        }

        .arrow-left {
            left: 0;
        }
        .slide-option{
            position: absolute;
            bottom: 10px;
            width: 100%;
            left: 0;
            text-align: center;
        }
        .slide-option span{
            display: inline-block;
            width: 14px;
            height: 14px;
            border-radius: 100%;
            background: #ccc;
            margin: 0 10px;
        }
        .slide-option .active{
            background: #09f;
        }
    </style>
</head>
<body>
<div class="slide-img clear" id="slide-img">
    <!--用tran这个class控制ul是否含有过渡效果，样式已经写好-->
    <ul id="slide-img-ul">
        <!--遍历出来的图片-->
        <li style="width: 1000px;"><a href="javascript:;"><img src="images/timg1.jpg" class="slider-img"/></a></li>
        <li style="width: 1000px;"><a href="javascript:;"><img src="images/timg2.jpg" class="slider-img"/></a></li>
        <li style="width: 1000px;"><a href="javascript:;"><img src="images/timg3.jpg" class="slider-img"/></a></li>
        <li style="width: 1000px;"><a href="javascript:;"><img src="images/timg4.jpg" class="slider-img"/></a></li>
    </ul>
    <div class="slide-option">
        <span></span>
        <span></span>
        <span></span>
        <span></span>
    </div>
    <div class="slide-arrow">
        <div class="arrow-left"></div>
        <div class="arrow-right"></div>
    </div>
</div>
</body>
<script type="text/javascript">
    window.onload=function () {
        var oUl=document.querySelector('#slide-img-ul');
        var oLi=oUl.querySelectorAll('li');
        var oSpan=document.querySelector('.slide-option').querySelectorAll('span');
        var oArrowLeft=document.querySelector('.arrow-left');
        var oArrowRight=document.querySelector('.arrow-right');
        oUl.style.width='4000px';
        oArrowLeft.addEventListener('click',function () {
            switchDo('reduce');
        })
        oArrowRight.addEventListener('click',function () {
            switchDo();
        })
        var timer=null,nowIndex=0;
        function switchDo(reduce){
            clearInterval(timer);
            //设置样式
            oUl.style.transform='translate3d(-'+(1000*nowIndex)+'px,0,0)';
            for (var i=0;i<oSpan.length;i++){
                if(i===nowIndex){
                    oSpan[i].className='active';
                }
                else{
                    oSpan[i].className='';
                }
            }
            //根据reduce判断this.nowIndex的增加或者减少！
            if(reduce==='reduce'){
                if(nowIndex===0){
                    nowIndex=oLi.length-1;
                }
                else{
                    nowIndex--;
                }
            }
            else{
                if(nowIndex===oLi.length-1){
                    nowIndex=0;
                }
                else{
                    nowIndex++;
                }
            }
            timer=setInterval(function () {
                switchDo();
            },4000)
        }
        switchDo();
    }
</script>
</html>